Loud speaker for radio receiving sets



Oct. 12 1926.

' F. w. cooLEY LOUD SPEAKER FOR RADIO RECEIVING SETS Filed March 8,

&

INVENTOR.

f/rED W. (300.15). 277/05 flrro NE).

Patented Get. 12, 1926.

UNITED STATES FRED W. COOLEY, 0F MINNEAPOLIS, MINNESOTA.

LOUD SPEAKER FOR RADIO RECEIVING SETS.

Application filed March 8, 1924. Serial No. 697,777.

This invention relates to a loud speaker adapted to be used with a sound reproducing machine and while the device may have various applications it particularly is designed for use with a radio receiving set. As is well known, loud speakers are now commonly used with such radio sets. A loud speaker should be constructed so as to give a minimum interference with the sound waves produced and to direct and transmit the waves so that the reproduced sound will be heard clearly and distinctly.

It is an object of this invention to provide a loud speaker of simple construction comprising a sound reproducing device such a the telephone reproducer commonly used with radio sets and having a passage leading from said reproducer ('on'ununicating with anamplifying chamber, in which passage is placed a tone modifier.

It is a further object of the invention to secure the sound reproducing device or telephone reproducer against the portion of the loud speaker having the said passage therethrough, gaskets or washers of yielding and also of hard elastic material being disposed between said telephone and mem ber.

These and other objects and advantages of the invention will more fully be set forth in the following description made in connection with the accompanying drawings in which like reference characters refer to the same parts throughout the different views, and in which,

Fig. 1 is a view in longitudinal central vertical section through the device;

Fig. 2 is a view in front elevation of the device;

Fig. 3 is a partial vertical section such as shown in Fig. 1, bein on an enlarged scale, and illustrating a s ight modification;

Fig. 4 is a partial view in front elevation, as seen from the right of Fig. 3;

Fig. 5 is a vertical section taken on line 55 of Fig. 3; and

Fig. 6 is a partial view similar to Fig. 4 in vertical section showing a modification.

Referring to the drawings, the device comprises a frame, which, in the embodiment of the invention illustrated, is in the.

form of a box having the side portions 1, the bottom portion 2 and top portion 3. Suitable cross pieces 4 extend across the bottom of the box, supporting the same, and

similar cross pieces 4 extend across the top, supporting the top or closing portion 3. The box has a rear wall or panel 5which, in the embodiment of the invention illustrated, is shown as composed of two separate panels 5 and 5". The box described has an open front side and a horn 6 is supported in said box with its large end directed outwardly of said front and open side, said horn being supported by brackets '7 secured thereto and to the rear wall 5. Said rear wall has an aperture extending therethrough of somewhat less diameter than the inner diameter of the small end of the horn 6 and a member composed of one or more blocks 8 is secured to the outer side of wall 5, which member has a passage extending thercthrough axially alined with and of substantially the same diameter as that through the wall 5. In the embodiment of the invention illustrated two blocks 8 are shown of which the one nearest the horn 6 will be called the inner block and the other one the outer block. This passage through blocks 8 and wall 5 is, in effect, a conduit leading to the small end of born 6. The outer block 8 has secured in the passage therethrough a cylindrical tube 9, the end of said tube disposed in said block fitting and being secured therein. The tube 9 extends through the passage in the other block 8 and in the wall or panel 5 and terminates with its front edge substantially flush with the inner side of the wall or panel 5 the tube being slightly reduced in diameter forward of the block 8 so that its outer side is spaced from the wall of the passage through the inner block 8 and the wall 5. In the embodiment of the invention illustrated, the aperture or passage through the outer block 8- is also somewhat smaller than through the inner block 8 and wall 5. An inner cylindrical tube 10 is secured in the tube 9 and has its outer wall spaced from the inner side of tube 9 throughout practically its whole extent. The tube 10 has secured thereto springs 12, by headed and nutted screws 11 which pass through said tube and through spacing members 12 disposed between the outer side of said tube and spring members 12. The springs 12 are of considerable width and are disposed between tubes 9 and 10 with their ends pressing against the interior of tube 9. The springs 12 nor- .mally are under stress so that tubes 9 and 10 are both under stress. Said spring being attached to tube 10 by the screws 11, the springs are under tension between said tubes. The springs will exert a pull upon the tube 10 and this will not be at'tectedhv the presence of post i The tubes rre not distorted by the stress but the material of the tubes placed in a stressed condition The tube 9 forms the base 01. reaction to springs 12 and the pressure of the springs against this tube will place the material of this tube 9 under tension. The spacing members 12 are preferably of non-elastic material such as adhesive tape or waxed leather. The springs 12 in Fig. 1 are shown as at the forward end of tubes 9 and it). while in Fig. 23 they are shown adjacent the rear end it said tubes. A post 13 extends dian'ietricallv across tube adjacent screws ll.

As shown in Fig. 6. one oi the springs 12 ma be omitted and a block or lug 1d of resilient material substituted therefor.

The sound reproducing device such as the ordinary telephone rein'oducer now commonly used with radio receiving sets, illustrated as l and disposed at the outer side oi the outer block 8. A washer or gasket 20. n-el'erablv ot' v'iclding material, is placed against the outer side of the outer block 8, wli ..h washer is contacted by a diaphragm washer 21 of comparatively hard elastic material. scch as mica or metal. The dia phra ni washer 21 is. in turn. contacted by another yielding? washer 22 against which the outer side of the phone 19 en; re s. The said ephone reproducer 19 is held in place by sets or clamps 21-; and 24 supported bi screws engaging in the outer block 8. The electrical conductors 25 are shown com.- municating with the telephone reproducer 19. The member 21 is engaged at its central portion. by a headed and threaded sleeve 26 which is screwed into the vt'rontof the telephone rcproducer 19. a. washer 27 ot' yielding material being disposed between the menil'ier 21 and the front face of the telephone reproducer 19. The sleeve 26 has a central opening therein alined with the usual opening in such a telephone reproducer. It will thus be seen that the opening through diaphragm 21 is small compared with that through washers and 22, which latter opening is of the same diameter or substantiallv the same diameter as the passage through block The provision of the diaphragm 21 greatly augments the sound so that a lender tone is secured. It will be noted that the horn (3, tubes 9 and 10. as well as the passage in which they are dis posed and the telephone reprodu'cer 19 are all in aiial alinement. A casing 28 surrounds members 8 and 9. I

in operation. the telephone reproducer 19 will be connected to the radio apparatus as usual by the contacts and the sound will be l'GPl'OfllltCtl by said telephone reproducer. The sound. wares formed will pass through the tubes 9 and it). 'lhese tubes are preterably made oi well seasoned wood of certain hinds having a high degree ot resiliency. The sound wares passing through the tubes cause the same to vibrate. The said tubes. as stated. are under stress and the same have a softening and modil'ymg ctl'cct on the sound so that when the same is il'lllSITllliGtl through the horn or amplifying chamber (3 the sound issues in clear and distinct tones. .is the sound waves exert their pressure in both directions. it as found neces ar to provide the gasket disks or washers 2t). 21. and 24. as well as the washer 27. These yielding disks apparently deaden a certain portion of the sound or eliminate certain ofii'ccts oi the wares so that the main volume o't sound passing through the, device is not intci'tcred with.

From the above description it is seen that applicant has provided a simple and very efiicient loud speaker adapted for use with radio or other sound rcproduciiu. apparatus. The device has been amply tested and demonstrated in actual practice and :l'ound to be very cliicient. The particular tone moditicr used is in some respects like that disclosed in applicants prior Patent X0. 1.423.832 granted Jul 2:). 1922.

It; will. ot" course. he uiulerstozul. that various changes may be made in the form, details. arrangement and proportions of the parts without departing from the s ope of applicants invention. which. generally stated. consi. in. a device capable o't carrying out the objects above set forth, such as shown. described and set forth in the appended claims.

hat is claimed is:

.l. A. loud speaking apparatus adapted to be used with a sound reproducer having in combination. a frame. a horn supported thereon, a member a djacent said horn having a passage opening into the smaller end of said horn. a resilient tube supported in said passage. means. normally placing said tube under stress. a diaphragm of thin rigid material at the other end of said men'iber and passage having a central opening alining with said passage and adapted to be disposed adjacent said reproducer.

2. The stri'icture set forth in claim 1, and means at said other end of said i'nembcr for holding said sound reproducer in close proximity to said diaphragm in axial alinemcnt with said horn and passage.

3. A loud speaker apparatus adapted to be used with a sound reproducer having in combination. a frame. a horn supported thereon, a block supported on said frame. said block and frame having a passage therethrough communicating with the small end of said horn, a resilient tube supported in said passage with the larger part of its periphery uiurontacted by the walls of said passage, means placing said tube under stress, a diaphragm of thin rigid and elastic material having a central opening therein alined with said passage at the side of said block opposite said horn, a washer of comparativel y soft elastic material between and in contact with said diaphragm and block, and means for holding a sound reproducer in close proximity to said diaphragm.

4. A loud speaker apparatus adapted to be used with a sound reproducer having in combination, a frame, a horn supported thereon, a conduit leading to the small end of said horn, a resilient tube in said conduit means for placing said tube under stress, a washer of: yielding material abutting the end of said conduit remote from said horn and having an opening of substantially the same size as the opening through said conduit, a diaphragm washer of hard elastic material contacting said washer, a third washer of comparatively soft yielding material contacting said diaphragm washer and having an opening thereinsubstantially the same size as that of said first mentioned washer, and means on said block for holding said sound reproducer in contact with said third washer.

A loud speaker for sound reproducing machines comprising a frame, a horn supported thereon and abutting said frame at its small end, a block mounted on said frame, a passage extending through said block and frame of smaller diameter than the opening at the small end of said horn and communicating with said small end, a tube of elastic material mounted to extend into said passage and spaced from the walls thereof for the greater part of its length, a

.second tube of elastic material disposed in said first mentioned tube, and resilient means secured to one of said tubes and engaging the other to hold said tubes properly spaced and place the same under tension, said tubes having free ends terminating substantially flush with the small end of said horn.

6. A loud speaker apparatus adapted to be used with a sound reproducer having in combination, a frame, a horn supported thereon, a member supported on said frame, said member and frame having a passage therethrough in axial alinement with said horn and communicating with. the small end thereof, a resilient tube fitting in and secured in the rear end of said passage remote from said born but spaced from the walls of said passage for the greater part of its length,

a second resilient tube secured in and axially alined with said tube and spaced from and parallel with the walls thereof, means for placing the second tube under stress, and means on said member for holding a sound reproducer in close proximity to said member in alinement with the end of said passage opposite said horn.

7. A loud speaking apparatus adapted to be used with a sound reproducer having in combination, a frame, a horn supported thereon, a block adjacent said frame. said block and frame having alined passages therethrough, a tone modifier carried. by said block and disposed in said passages, an apertured diaphragm adjacent said block at the end of said passage opposite said horn, and washers of comparatively soft resilient material at each side of said diaphragm contacting the edges of the same and contacting said block, said horn, passages, diaphragm and washers being in axial alinement,

8, A loud speaker for sound reproducing machines comprising a frame, a horn supported thereon, a member supported on said frame, said member and frame having a passage therethrough in axial alinement with said horn and communicating with the small end thereof, a resilient tube fitting in and secured in the rear end of said passage remote from said horn but spaced from the walls of said passage for the greater part of its length, a second resilient tube secured in and axially alined with said tube and spaced from the walls thereof, means for placing said second tube under stress, and a sound reproducer at the outer side of said member facing into said passage and axially alined therewith.

9. A loud speaking apparatus adapted to be used with a sound reproducer having in combination, a horn, a member adjacent said horn having a longitudinal passage therethrough communicating with and axially alined with the small end of said horn, aresilient tube secured in said passage and spaced from the walls thereof throughout the greater portion of its length and a small resilient tube removably held in and spaced from the walls of said first mentioned tube, said device being adapted to have a sound reproducer disposed adjacent said member at the side opposite said horn and alined with the passage therethrough.

10. The structure set forth in claim 9, said smaller tube having a post extending dia metrically therein and through one side thereof, a spring engaged, by said post adapted to be disposed within said outer tube and to frictionally engage the wall of said smaller tube to hold the smaller tube in position.

11. A loud speaking apparatus adapted to be used with a sound reproducer having in combination, a rigid block having a passage therethrough, a tube of elastic. material secured at one end in said passage and spaced from the wall thereof for the greater part of its length, a smaller tube within said tube spaced from and parallel with the walls thereof. a thin diaphragm o't hard elastic material adjacent said block and having a central aperture alined with the passage the "*"hrough. washers of comparatively sott resilient material at each side of said diaphragm, one oi which contacts said i)l()(5l\'. and means tor holding a sound reproducer closely adjacent the washer at the side of said diaphragm opposite said block.

ii. A. loud speal-zing apparatus adapted to he used with a sound reprodueer having in combination, a panel having an aperture therethrough, a comparatively long member extending from the rear of said panel and having a passage therethrough alined with the aperture in said panel, a tube of elastic material secured in the rear of said passage and spaced from the wall thereot "tor the greater part of its length, means for placing said tube under stress, a diaphragm at the rear end of said member and mssage having a comparatively small cylindrical opening, therein washers t comparatively soft resilient material at each side of said diaphragm engaging the edges thereof, one of which engages said member. and means on said member 'l'or holding the sound reproducer closely adjacent the other of said washers.

1 3. A loud speaker for sound reproducing machines having in combination, a panel having an opening therein, a member ad jacent said panel having a passage therethrough alined with said opening, a tube of elastic material supported in said passage and spaced from the walls thereof for the greater portion of its length, and a diaphragm of hard elastic material at the side of said member opposite said panel and having a small opening theretln'ough centrally alined with said passage, said loud speaker being adapted to be placed adjacent a sound reproduce]: with said reproducer closely adjacent to and alining with the opening in said diaphragm.

ll. A sound modifying apparatus comprising a member having a passage therethrough, a diaphragm of hard elastic material at one side of said member having a. comparatively small opening therethrough axially alined with said passage, a sound modifier disposed in said passage and means on said member adapted to hold a sound reprodueer in close 'n'oximity to said diaphragm and axially alined with the opening therein.

15. A loud speaker for sound reproducing machines comprising a frame, a horn supported thereon, a member supported on said trame said member and frame having a passage tlierethrongh in axial alinement with said horn and connniinicating with the small end thereof, a resilient tube fitting in and secured in the rear end of said passage remote from said horn but spaced from the walls thereof and parallel to said walls for the greater part of its length, a resilient tube secured in and axially alined with said tube and spaced. from the walls thereot, a plate spring secured to said latter tube and contacting said first mentioned tube, said spring being normally under tension.

In testimony whereof I aflix my signature.

FRED lV. COOLEY. 

